An air strike on Yemen’s capital Sanaa killed 12 people including six children on Friday, rescuers said.

The attack on the Faj Attan area on the outskirts of the city also severely damaged at least two buildings, reducing much of them to rubble, they said. Residents and rescuers dug through debris to retrieve the bloodied, dust-covered bodies of several children, who appeared aged under 10 years old.

People at the scene told Reuters The warplanes were believed to be from a Saudi-led Arab coalition waging a 2-1/2-year-old campaign against the Iran-aligned Houthi movement for control of the country in a war which has killed at least 10,000 people.

The Houthis and their ally, former president Ali Abdullah Saleh, control much of the north of the country, including Sanaa. Yemen’s internationally-recognized government is backed by the Saudi-led military alliance and is based in the south.

The United Nations human rights office called on Friday for an independent investigation into air strikes by the Saudi-led coalition on a hotel near Sanaa on Wednesday that killed more than 30 people, as well as civilians in two other hits.